Abstract : The radical HO2 was established as an intermediate in the hydrogen-oxygen reaction. The radical configuration is considered as that of an isosceles triangle with the O-H distance 1.8 angstrom units and the O-O distance 2.456 angstrom units. Electron states are described by molecular orbitals. An attempt was made to mathematically determine the total energy of the ground state of the radical, the energy levels of its ground state, the promotion of charge in each of the atoms involved, the bonding properties of the various orbitals, and the approximate energy of the lower-lying excited states. A correlation of these results with those for the oxygen molecule is presented. The calculations involve several assumptions.